v0.94: history retention, saved-history access, universal web-agent observation

[KAVentures]

Summary

This builds the full post-v0.93 history/agent package on top of main:

• explicit local history retention for human and agent evidence (ephemeral / N days / forever)
• upgrade-safe defaults that preserve existing retained history
• session-aware expiry/deletion with durable tombstones so delayed/buffered events cannot recreate deleted sessions
• History navigation/API/UI, selected-range export, and list_history MCP navigation
• saved-history AI access as a separate, time-limited lease from local retention
• central MCP transport guard that bounds historical reads to the user-authorized range
• Context Pulse generation invalidation after deletion/retention/access changes
• structural browser-agent lifecycle adapters for ChatGPT, Claude web, Microsoft Copilot, Lovable, and Gemini
• projection of those browser runs into the existing vendor-neutral agent evidence contract with observation_level=os_observed
• no prompt/response/tool-content/typed-text/clipboard-content capture and no browser permission expansion
• version bump to 0.94.0 and browser sensor 1.12.0-v94-agent-lifecycle

Privacy invariants

• Capture/retention and AI disclosure remain separate controls.
• General typed text and clipboard contents remain uncaptured.
• Browser agent adapters send only structural lifecycle state and opaque run IDs; no DOM/user/model content is transmitted.
• Missing hidden agent signals remain not observed, not inferred as absent.
• Existing canonical evidence remains primary; History and findings are navigation/derived layers.

CI focus

Please exercise the full Python matrix, browser JS privacy/syntax tests, packaging, and Gateway container compatibility before merge.